CN102487110A - LED packaging method - Google Patents

Abstract

A light-emitting diode packaging method, comprising: providing a packaging substrate, the packaging substrate has at least one accommodating groove; fixing the light-emitting diode chip on the bottom of the accommodating groove; coating the packaging glue in the accommodating groove and covering the light-emitting The diode chip; and using a mould, pressing the mold on the surface of the encapsulant to make the surface of the encapsulant smooth, and then separating the mold from the encapsulant. The above encapsulation method presses the mold on the surface of the encapsulant, which can overcome the surface tension existing in the curing process of the encapsulant, thereby avoiding the concave surface of the encapsulant, and obtaining an LED encapsulation structure with expected optical properties and appearance.

Description

LED Packaging Method

technical field

The invention relates to a packaging method of a semiconductor element, in particular to a packaging method of a light emitting diode.

Background technique

Semiconductor light-emitting diodes, with their advantages of high luminous efficiency, small size, light weight, and environmental protection, have been widely used in various fields, such as indicator lights, lighting lamps, and display screens.

Before the light-emitting diode is applied to the above fields, the light-emitting diode chip needs to be packaged to protect the light-emitting diode chip, thereby obtaining higher luminous efficiency and longer service life. The packaging of light-emitting diodes usually includes steps such as die bonding, glue filling, and baking. Among them, die-bonding is to fix the LED chip in a groove of the package substrate; potting is to cover the LED chip with liquid packaging material by injection or molding, and the light emitted by the LED chip can pass through the package. The material and the reflection through the inner wall of the groove reach the outer space.

However, during the curing process of the liquid encapsulation material, due to the surface tension, the surface of the cured encapsulation material shrinks inwardly, causing the encapsulation layer to be concave, which affects the optical performance and appearance of the LED encapsulation structure.

Contents of the invention

In view of this, it is necessary to provide a packaging method for light emitting diodes, and the packaging structure of light emitting diodes obtained by the packaging method has expected optical properties and appearance.

A light emitting diode packaging method, comprising:

providing an encapsulation substrate, the encapsulation substrate has at least one accommodating groove;

fixing the light emitting diode chip on the bottom of the containing tank;

coating the encapsulation glue in the accommodating groove and covering the light emitting diode chip; and

Using a mold, press the mold on the surface of the encapsulant to make the surface of the encapsulant flat, and then separate the mold from the encapsulant.

The above encapsulation method presses the mold on the surface of the encapsulant, which can overcome the surface tension existing in the curing process of the encapsulant, thereby avoiding the concave surface of the encapsulant, and obtaining a light emitting diode encapsulation structure with expected optical properties and appearance.

The present invention will be further described below in conjunction with specific embodiments with reference to the accompanying drawings.

Description of drawings

FIG. 1 to FIG. 3 are schematic diagrams of each step of the LED packaging method and the LED packaging structure obtained from each step according to an embodiment of the present invention.

FIG. 4 is a schematic diagram of the steps of a method for packaging light emitting diodes according to another embodiment of the present invention.

Description of main component symbols

Packaging Substrate 10

First Surface 101

Second Surface 102

Storage tank 12

Inner wall 121

Circuit structure 14

LED chip 20

Die Bonding Adhesive 201

Encapsulant 30

Surface 301

Mold 40, 41

Press arm 42

Release film 50

Detailed ways

Please refer to FIG. 1 , firstly, a packaging substrate 10 is provided. The packaging substrate 10 can be made of insulating materials such as ceramics with good thermal conductivity. The packaging substrate 10 has a first surface 101 and an opposite second surface 102 , the first surface 101 can be, for example, a top surface, and the second surface 102 can be, for example, a bottom surface. There is at least one accommodating groove 12 on the top surface, the accommodating groove 12 has an inner wall 121 , and the inner wall 121 is inclined relative to the surface of the packaging substrate 10 . The accommodating groove 12 is used for accommodating the LED chips 20 , and the number of the accommodating grooves 12 can be changed according to the quantity and arrangement of the LED chips 20 . The accommodating groove 12 may be in the shape of an ellipse, a truncated cone, or the like. Further, a circuit structure 14 is formed on the bottom surface, and the circuit structure 14 penetrates the packaging substrate 10 and is exposed at the bottom of the accommodating groove 12 .

Next, the LED chip 20 is fixed on the bottom of the containing groove 12 . The light-emitting diode chip 20 is electrically connected to the circuit structure 14 on the packaging substrate 10. In this embodiment, a flip-chip method is used to separate the two electrodes of the light-emitting diode chip 20 from a die-bonding glue 201, such as silver glue. It is connected to the circuit structure 14 . In other embodiments, the light-emitting diode chip 20 may also be connected to the circuit structure 14 by die bonding. Preferably, the LED chip 20 is a blue light chip.

Referring to FIG. 2 again, the encapsulation glue 30 is coated in the receiving groove 12 and covers the LED chip 20 . Preferably, the encapsulant 30 may also contain phosphor powder, and the light emitted by the LED chip 20 after exciting the phosphor powder and the blue light emitted may be mixed to form white light. Since the encapsulant 30 has certain fluidity, the surface 301 of the encapsulant 30 tends to be concave during the curing process due to the existence of surface tension. Therefore, the present invention provides a mold 40 before the encapsulation glue 30 is cured after coating the encapsulation glue 30, so that the mold 40 is pressed on the surface 301 of the encapsulation glue 30, and the external force applied to the encapsulation glue 30 by the mold 40 is overcome. The surface tension of the encapsulant 30 makes the encapsulant 30 flat after being cured, thus ensuring the expected optical performance and appearance of the LED encapsulation structure.

In this embodiment, a pressing arm 42 protrudes downward from the surface of the mold 40 , and the pressing arm 42 presses on the periphery of the surface 301 of the encapsulant 30 and adjoins the inner wall 121 of the accommodating groove 12 . Due to the surface tension, the center of the surface 301 of the encapsulant 30 tends to be more concave, so the encapsulant 30 can be destroyed by pressing on the periphery of the surface 301 of the encapsulant 30 so that the encapsulant 30 can be squeezed and flow to the center. concave trend.

Please refer to FIG. 3 again. After the surface 301 of the encapsulant 30 is flattened and cured, the mold 40 is separated from the encapsulant 30 to obtain the LED encapsulation structure. Preferably, the surface 301 of the encapsulant 30 is even with the top of the accommodating groove 12 . Further, a layer of release film 50 is provided on the surface of the pressing arm 42 of the mold 40 in contact with the encapsulant 30 , which facilitates better separation from the encapsulant 30 during demoulding.

It can be understood that when the mold 40 presses the surface 301 of the encapsulant 30 , it is not limited to the above-mentioned embodiment of pressing the peripheral surface 301 of the encapsulant 30 . Please refer to FIG. 4 , the mold 41 used in another embodiment of the present invention has a flat surface, and is pressed on the entire surface 301 of the encapsulant 30 , which can also make the surface 301 of the encapsulant 30 flat. Further, to facilitate demoulding, a layer of release film 50 may also be provided on the surface of the mold 41 .

Claims (9)

1. LED encapsulation method comprises:

The encapsulation base material is provided, has at least one storage tank on this encapsulation base material;

Light-emitting diode chip for backlight unit is fixed in the storage tank bottom;

Coat in the storage tank packaging plastic and covering luminousing diode chip;

It is characterized in that, also comprise the use mould, mould is pressed put after the surface of packaging plastic makes the packaging plastic surfacing, again mould and packaging plastic are broken away from.

2. LED encapsulation method as claimed in claim 1 is characterized in that: the surface of said mould convexes with to press puts arm, said pressure put arm press put the peripheral surface of packaging plastic and with the inwall adjacency of storage tank.

3. LED encapsulation method as claimed in claim 2 is characterized in that: said pressure is put the surface that contacts with packaging plastic on the arm and is provided with fractal film.

4. LED encapsulation method as claimed in claim 1 is characterized in that: the surfacing of said mould is also pressed and is put on the whole surface of packaging plastic.

5. like claim 1 or 4 described LED encapsulation methods, it is characterized in that: the surface of said mould is provided with fractal film.

6. LED encapsulation method as claimed in claim 1; It is characterized in that: said light-emitting diode chip for backlight unit is a blue chip; Comprise fluorescent material in the said packaging plastic, the light that sends behind the said light-emitting diode chip for backlight unit excitated fluorescent powder and institute's blue light-emitting are mixed into white light.

7. LED encapsulation method as claimed in claim 1 is characterized in that: also form circuit structure on the said encapsulation base material, be electrically connected with circuit structure formation when light-emitting diode chip for backlight unit is fixed in the storage tank bottom.

8. LED encapsulation method as claimed in claim 7 is characterized in that: said light-emitting diode chip for backlight unit is fixed on the encapsulation base material to cover brilliant mode.

9. LED encapsulation method as claimed in claim 1 is characterized in that: the surface of said packaging plastic is equal with the top of storage tank.

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